In order to dye keratinous fibers such as the hair, there have been widely used so-called oxidation dyes comprising a combination of a developer with a coupler. Dyeing with such an oxidation dye is performed by utilizing the ability of a so-called oxidation colorant, which is formed by the oxidation coupling between a developer and a coupler, to strongly dye, for example, the hair.
Examples of these developer which have been generally used include p-phenylenediamine derivatives, p-aminophenol derivatives, diaminopyridine derivatives, 4-aminopyrazolone derivatives and heterocyclic hydrazone derivatives. Examples of the couplers which have been employed include .alpha.-naphthol, o-cresol, m-cresol, 2,6-dimethylphenol, 2,5-dimethylphenol, 3,4-dimethylphenol, 3,5-dimethylphenol, benzcatechin, pyrogallol, 1,5-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 5-amino-2-methylphenol, hydroquinone, 2,4-diaminoanisole, m-toluylenediamine, o-aminophenol, resorcin, resorcin monomethyl ether, m-phenylenediamine, 1-phenyl-3-methyl-5-pyrazolone, 1-phenyl-3-amino-5-pyrazolone, 1-phenyl-3,5-diketopyrazolidine, 1-methyl-7-dimethylamino-4-hydroxyquinolon-2-one, 1-amino-3-acetylacetoamino-4-nitrobenzole, m-aminophenol, 4-chlororesorcin, 2-methylresorcin, 2,4-diaminophenoxyethanol, 2,6-diaminopyridine, 3,5-diaminotrifluoromethylbenzene, 2,4-diaminofluorobenzene, 3,5-diaminofluorobenzene, 2,4-diamino-6-hydroxypyrimidine, 2,4,6-triaminopyrimidine, 2-amino-4,6-dihydroxypyrimidine, 4-amino-2,6-dihydroxypyrimidine, 4,6-diamino-2-hydroxypyrimidine, p-nitro-o-phenylenediamine, 2-amino-5-nitrophenol, p-nitro-m-phenylenediamine, o-nitro-p-phenylenediamine and 2-amino-4-nitrophenol.
However conventional oxidation dyes are not always satisfactory in chroma, coloring power or fastness.
In the case of dyes for bluish colors, for example, m-phenylenediamine or 2,6-diaminopyridine can impart a color tone of a high chroma when used as a coupler. However, it is disadvantageous in serious color change/fading after dyeing or discoloration after shampooing. That is to say, there have been known hitherto only a few keratinous fiber dye compositions being satisfactory in all of chroma, coloring power and fastness.